Two useful scenarios for aliases:
1. Multiple foreign keys to the same model
For example, your photos
table has two fields: created_user_id
& modified_user_id
var $belongsTo = array(
'CreatedUser' => array(
'className' => 'User',
'foreignKey' => 'created_user_id',
...
),
'ModifiedUser' => array(
'className' => 'User',
'foreignKey' => 'modified_user_id',
...
),
);
2. Creating logical words specific to your application's domain
Using the conditions field in the array, you could specify different kinds of models:
var $hasMany = array(
'ApprovedUser' => array(
'className' => 'User',
'foreignKey' => 'group_id',
'conditions' => array(
'User.approved' => 1,
'User.deleted' => 0
),
...
),
'UnapprovedUser' => array(
'className' => 'User',
'foreignKey' => 'group_id',
'conditions' => array(
'User.approved' => 0,
'User.deleted' => 0
),
...
),
'DeletedUser' => array(
'className' => 'User',
'foreignKey' => 'group_id',
'conditions' => array('User.deleted' => 1),
...
),
);
In the above example, a Group model has different kinds of users (approved, unapproved and deleted). Using aliases helps make your code very elegant.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…